Lecture 162:- Let's Code Sparse Matrix using C++ Continued

Sure! Continuing from the previous C code, let's complete the program for representing and adding two sparse matrices using the Compressed Sparse Row (CSR) format. We'll use arrays to store the non-zero elements, row indices, and column pointers. Additionally, we will provide a function to print the resulting sparse matrix.

cCopy code

#include <stdio.h> #include <stdlib.h> // Structure to represent a non-zero element in the sparse matrix struct Element {    int row;    int col;    int value; }; // Function to add two sparse matrices in CSR format struct Element* add_sparse_matrices(const struct Element* A, int sizeA, const struct Element* B, int sizeB, int* sizeC) {    int capacity = sizeA + sizeB;    struct Element* C = (struct Element*)malloc(capacity * sizeof(struct Element));    int i = 0; // Index for matrix A    int j = 0; // Index for matrix B    int k = 0; // Index for matrix C    while (i < sizeA && j < sizeB) {        if (A[i].row < B[j].row || (A[i].row == B[j].row && A[i].col < B[j].col)) {            C[k] = A[i];            i++;        } else if (A[i].row > B[j].row || (A[i].row == B[j].row && A[i].col > B[j].col)) {            C[k] = B[j];            j++;        } else {            C[k].row = A[i].row;            C[k].col = A[i].col;            C[k].value = A[i].value + B[j].value;            i++;            j++;        }        k++;    }    // Copy the remaining elements from A (if any)    while (i < sizeA) {        C[k] = A[i];        i++;        k++;    }    // Copy the remaining elements from B (if any)    while (j < sizeB) {        C[k] = B[j];        j++;        k++;    }    *sizeC = k;    return C; } // Function to print the sparse matrix void print_sparse_matrix(const struct Element* matrix, int size) {    printf("Row\tCol\tValue\n");    for (int i = 0; i < size; i++) {        printf("%d\t%d\t%d\n", matrix[i].row, matrix[i].col, matrix[i].value);    } } int main() {    struct Element A[] = { {0, 1, 5}, {1, 2, 10}, {2, 0, 3} };    int sizeA = sizeof(A) / sizeof(A[0]);    struct Element B[] = { {0, 1, 7}, {1, 1, 2}, {2, 0, 1} };    int sizeB = sizeof(B) / sizeof(B[0]);    int sizeC;    struct Element* result = add_sparse_matrices(A, sizeA, B, sizeB, &sizeC);    printf("Result Sparse Matrix:\n");    print_sparse_matrix(result, sizeC);    free(result);    return 0; }

In this code, we added a print_sparse_matrix function that takes the resulting sparse matrix and its size as inputs and prints it in a formatted manner with row, column, and value information.

The main function demonstrates the usage of the add_sparse_matrices function with two example sparse matrices A and B. The resulting sparse matrix is then printed to the console using the print_sparse_matrix function.

Again, remember to free the dynamically allocated memory for the result array using free() to avoid memory leaks.